Gas carbureting apparatus



April 18, 1944. s. P. JONES GAS CARBURE'IING APPARATUS Filed Nov. 2, 1942 2 Sheets-Sheet 1 gvwma/bo'v 60122 domes 24 VIIII IIIIIA April 18, 1944. s. P. JONES 2,346,763

' GAS CARBURETING APPARATUS Filed Nov. 2, 1942 2 Sheets-Sheet 2 V T! gi l: 4

4/ 47 62 56 P T 62 4 a 55 63 1-4.5 58

37 38 C 9 V arm 0mm 39 70 Sam 2? domes atented Apr. 18, 1944 UNITED STATES PATENT OFFICE 2,346,763 GAS CARBURETING APPARATUS Sam P. Jones, Dallas, Tex.

Application November 2, 1942, Serial No. 464,242

14 Claims.

carbureting apparatus which is particularly adapted for use with internal combustion engines and which will efliciently and accurately control the flow of fluid to said engine under all operating conditions; the apparatus being particularly useful with engines operating on gaseous, rather than liquid, fuel and being an improvement on the gas carbureting apparatus disclosed in my co-pending application, Serial No. 408,178, filed August 25, 1941.

As is well known, the usual carburetor includes a Venturi throat with the fuel and air inlets in advance of or upstream from said throat, where- .by .the vacuum or suction effect of the jet located in the throat is utilized to draw said air and fuel into the carburetor. The carburetor has its outlet end connected with the engine manifold and a butterfly control valve is disposedbetween the venturi and said manifold, whereby said valve is downstreamof the venturi. When the engine is operating, there is always a partial vacuum at the point-between the engine manifold and the butterfly valve because obviously said valve provides a restriction and this vacuum is proinches of mercury), and drops off gradually asthe load is applied until at full load, it reaches a minimum (approximately two inches or less of mercury).

When the engine is operating, there is also a partial vacuum at the throat of the venturi but since the venturi is disposed upstream from or in advance of the butterfly valve which provides the main restriction in the passage, this vacuum is considerably less than the vacuum between said valv and the manifold; in fact under no engine load when the butterfly valve is substantially closed or pinched down, the vacuum or suction efiect of the jet in the Venturi throat is practically negligible. As the load is increased and the butterfly opened wider, the vacuum at the venturi is proportionately increased until at full load maximum vacuum at the venturi is attained (approximately three inches of mercury). From the foregoing, it will be seen that the vacuum at the point between the butterfly valve and the engine manifold, which will hereinafter be referred to as the manifold vacuum is greater than the vacuum at the Venturi throat, hereinafter referred to as Venturi vacuum," under all operating conditions except when the engine is under full load. When the engine is under full load, the butterfly valve is wide open and the manifold vacuum has dropped off to minimum while the Venturi vacuum has increased to maximum.

It is the main object of the present invention to provide an improved carbureting apparatus for internal combustion engineshaving means for controlling the volume of fuel flowing to the carburetor of said engine, said means being actuated either by the manifold vacuum of the engine or by the Venturi vacuum of the carburetor, depending upon which of these vacuums is greater, whereby a positive and accurate actuation of the fuel control means is had under all operating conditions.

An important objectof the invention is to provide an improved gas carbureting apparatus for internal'combustion engines wherein a main fuel valve which controls the flow of gas to the carburetor isactuated by'a vacuum' responsive element which is adapted to be exposed to the manifold vacuum of the engine, together with a second vacuum responsive member which is exposed to the Venturi suction of the carburetor; the element and member being so arranged that each functions to actuate'the valve when the vacuum acting thereon exceeds the vacuum acting upon the other, whereby a sufliciently high vacuum for efiiciently andaccurately operating the valve under all engine loads is assured.

A particular object of the invention is to provide an improved carbureting apparatus, of the character described, having a vacuum responsive element subjected to the manifold vacuum and a second vacuum responsive element exposed to the Venturi vacuum, said elements being adapted to co-act with each other so that the relatively high manifold vacuum is utilized to control the main I fuel valve throughout all engine loads except gether with means for accurately maintaining a.

predetermined vacuum within said chamber whereby a positive control of the movemeht oi the element, as well as of the main fuel valve, may be accomplished to permit a sensitive control of the gas supply to the engine for idling; the apparatus being readily adjustable to vary the movement or travel of the element and fuel valve, whereby various idling mixtures in accordance with conditions, may be provided.

A still further object of the invention is to provide an improved apparatus of the character described, which is so constructed that the vacuum responsive element exposed to the Venturl vacuum co-acts with the vacuum responsive element exposed to the manifold vacuum and through such coaction causes the manifold vacuum to control the movement of the main fuel valve throughout the major portion of the operating range of the engine; this utilization of the manifold vacuum, which is relatively high, making possible the use of a spring or other resilient means on the main valve for urging said valve to a closed position, whereby when the engine is not operating, positive closing of said main valve is assured.

A construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

Figure 1 is a view, partly in section and partly in elevation of a gas carbureting apparatus, constructed in accordance with the invention and combined with the gas mixer of an internal combustion engine,

Figure 2 is an enlarged, transverse, vertical sectional view of the main fuel valve and its associate parts, said valve being in a closed or seated position.

Figure 3 is a. view, similar to Figure 2, with the fuel valve in a raised or open position,

Figure 4 is an enlarged, vertical sectional view of the main fuel valve and its operating diaphragm,

Figure 5 is a horizontal cross-sectional view taken on the line 5-5 of Figure 2,

Figure 6 is an elevation of the vacuum control valve which is associated with the operating diaphragm chamber, and

Figure 7 is a view similar to Figure 6 showing a modified form of said valve.

In the drawings, the numeral [0 designates the body or housing of a gas mixer which is adapted to be connected to the inlet manifold Illa of an internal combustion engine (not shown). The body or housing is shown in the form of an elbow and the lateral or horizontal portion of the housing is open to provide an air inlet ll,.the usual choke valve I2 being mounted adjacent this inlet in the usual manner. A Venturi sleeve I3 is mounted within the vertical portion of the housing in and the butterfly throttle valve I4 is mounted above the Venturi sleeve on a rotatable shaft IS. The upper portion of the housing is formed with an outwardly directed annular flange "5, whereby said housing may be readily connected to the intake manifold of the engine.

A T coupling I1 is mounted in the lower portion of the housing, being welded or otherwise suitably secured thereto. The lateral leg of the coupling has a gas inlet pipe [8 connected there to whereby gas from a suitable source may be supplied to the coupling. From the coupling,

the gas flows upwardly through an inlet tube 19 and this tube has its upper end terminating within the lower portion of the Venturi throat which is formed by the sleeve 13. A suitable valve (not shown) is mounted within the coupling l1 and its position is controlled by an adjusting screw 20 which extends outwardly from the lower end of the coupling; by adjusting the screw 20, the volume of gas flowing upwardly through the inlet tube l9 may be accurately controlled.

The mixer which is shown in Figure l is of standard construction and the engine suction is depended upon to draw air through the housing from the inlet H and also to draw gas upwardly through the inlet tube I9. The gas and air admixes and flows through the intake manifold to the engine (not shown).

:Adjacent the throttle valve M, the housing I0 is provided with an orifice 2| and a coilar 22, which is preferably integral with the wall of the housing, surrounds the orifice and extends outwardly therefrom. As is clearly shown in Figure 1, the bore 23 of the collar communicates with the orifice 2| and the outer end of said bore is screw threaded. When the engine is idling, the throttle valve I4 is in the position shown in Figure 1, that is, the valve is substantially in a. closed position and the orifice 2| is located thereabove, whereby the suction or partial vacuum above the throttle valve may act through the orifice. The vacuum at this point will be hereinafter referred to as the manifold vacuum For controlling the flow of fuel to the housing l0 and thereby control the gas-air ratio, an improved fuel control device A which forms Dart of the apparatus is connected to the gas line It which extends to the coupling I1 and then to the gas inlet tube IS. The opposite side of the device A has connection with a gas supply line 24 which extends from a suitable source of supply. The device A includes a cylindrical body 25 which has diametrically opposed collars 25 and 21 preferably formed integral therewith, and these collars are internally screw-threaded whereby the pipes l8 and 24 may be connected with the body. A transverse web 28 is located centrally within the body 25 (Figures 2 and 3) and is secured to the body by vertically extending supports 29, the supports and web being preferably integral with each other and with the body 25. The web 28 divides the interior of the body into an upper chamber B and a lower chamber C, the upper chamber communicating with the gas supply pipe 24 and the lower chamber C communicating with the gas line I8 which leads to the mixer. The Web is formed with a central or axial opening 30 which establishes communication between the chambers B and C and obviously, a flow of gas from the supply pipe 24 into the chamber B, then through the opening 30, chamber C and pipe l8 may occur.

The upper portion of the wall of the opening 30 is beveled to form a valve seat 3| which is arranged to be engaged by a valve element 32, said element having its outer peripheral portion formed of flexible or elastic material 33. Manifestly, the valve element controls the flow of gas through the opening 30. The valve element is threaded onto the lower portion of a tubular stem 34, being retained thereon by a lock nut 35. The lower end of the stem 34 extends downwardly in a plane below the valve element, while the upper portion of said stem extends axially 76 through an opening 36 formed in the top of the body 25. The lower end of the stem 34 is guided through an opening 31 which is formed centrally of a guide bar 38, said guide bar being secured to the under side of the web 28 by bolts 39 and being spaced from the web by suitable spacing collars or washers 46. Manifestly, the guide bar guides the stem 34 and valve element 32 in its vertical movement.

The opening 36 in the upper end of the body 25 is closed by a hollow head or cap member 4| which is provided with an external annular base flange 42. The flange is adapted to be secured to the body by suitable bolts 43 which pass through the flange and are threaded into the body, as is clearly shown in Figure 4. The head or cap member is enlarged at its lower portion immediately above the flange to provide an enlarged internal chamber 44 and an axial bore 45 extends upwardly from this chamber. A laterally directed port 46 extends from the upper end of the bore 45 and has one'end of a line or pipe 41 threaded thereinto. The opposite end of the pipe or line 41 is connected into the collar 22 which is formed on the gas mixer body l and thus, a communication between the engin manifold and the port 46 of the head 4| is set up through the orifice 2| and line 41. Communication between the port 46 and chamber 44 is established through the bore 45 and also through a vertical passage 460. which is provided especially for. this purpose.

An upper vacuum responsive element which is illustrated as a diaphragm 48, is disposed within the chamber 44 and spans the opening 36 in the upper portion of the body. The peripheral portion of the diaphragm 48 is clamped between the base flange 42 and the body 25 and the central portion of the diaphragm is provided with an opening 49 through which the tubular valve stem 34 extends. Reinforcing washers 56 and surround the tubular stem 34 being disposed on op-.

' diaphragm is moved, a movement is imparted to the stem 34 and also to the valve element 32 mounted thereon. The lower end of the bore 45 of the head ii is formed with a counterbore, whereby an internal annular shoulder 54 is provided and a coiled spring 55 surrounds the housing 53 and is confined between this shoulder 54 and the upper washer 5| of the diaphragm. The spring 55 constantly exerts its pressure to urge the diaphragm and stem downwardly, whereby the valve element 32 which is carried by the stem is urged to a seated or closed position. It is pointed out that the tubular housing '53 which is secured to the stem 34 is of a slightly smaller diameter than the diameter of the bore 45, whereby the upper surface of the diaphragm 46 is exposed to the vacuum in the line 41 through the bore 45 as well as through the port 46a, such vacuum acting to lift the diaphragm against the tension of the spring 55.

The upper end of the housing 53 which is threaded onto the upper end of the tubular valve stem 34 is formed with an axial opening 56 whereby a communication between the chamber e below the web as within the body as and the upper end of the bore of the head may be had. For controlling the flow through the tubular valve stem and housing 53, a valve member V is slidably mounted within the upper portion of the housing. This member is clearly shown in Figure 6 and includes a cylindrical body 61 having vertical grooves or channel 58 in its outer surface. The lower end of the body is provided with a depending'stud 53, while the upper portion of said body is tapered or reduced to form a conical surface 60 and an upstanding pin 6| extends upwardly from this surface. The tapered surface 60 of the valve element is adapted to co-act with a valve seat 62 which is provided at the lower portion of the opening 56 in the tubular housing 53. A coil spring 63 is disposed within the housing 63 and is confined between the upper end of the tubular valve stem 34 and the underside of the valvebody 51, said spring constantly urging the valve member to a seated position. Manifestly, as the valve member moves relative to the seat 62, the volume flowing through the opening 56 and into the bore 45 of the head and then into the chamber 44, is accurately controlled. The amount of movement which the valve must undergo relative to its seat to admit a predetermined volume of flow is dependent upon the angle or inclination of the taper or incline 60 of the valve member. By changing this taper, the volume passing the open galve upon a predetermined movement of the member may be controlled and in Figure 7, a modified form of valve member i illustrated wherein a longer incline or taper 66a is illustrated.

For efiecting an opening of the valve member V upon an upward movement of the tubular valve stem 34 and the housing 53 which is secured thereto, a set screw 64 is threaded into the upper end of the head or cap member 4|. The

.extreme lower end of the screw 64 extends into the upper end of the bore 45 of the head above the upstanding pin 6| of the valve member and this lower end is adapted to co-act with said pin. It will be apparent that when the tubular valve stem 34 and the various parts secured thereto move upwardly, the valve member mounted within the housing 53 will also move upwardly. Such upward movement will cause the upstanding pin 6| on the valve member V to strike the lower end of the set screw 64 and any continued upward movement of the valve assembly will result in an unseating of said valve member, whereby a flow may occur from the chamber C below the web 26 and into the bore 45 and chamber 44 of the head 4|. Thus, if a vacuum is acting on the diaphragm 46 when the valve V is closed, an upward movement of the housing caused by the upward movement of said diaphragm will result in an unseating of the valve V and a soon as this occurs, the vacuum in the chamber 45 is relieved to halt upward movement of said diaphragm. It is obvious that when the housing 53 is in a lowered position, the distance betweenthe lower end of the set screw 64 and the pin 6| will determine the distance which the housing must travel before the valve V is opened and by adjusting the screw 64, this distance may be readily varied. After the valve V is unseated, the taper or inclination of the conical surface 60 thereof will control the volume of fluid which enters the bore 45 and chamber 44 upon a predetermined continued movement of the housing 53 and its associate parts. By varying the taper,

upon a predetermined travel of the housing 63 may be accurately controlled.

As explained, the upper diaphragm 48 is actuated by the vacuum in the engine manifold above the throttle valve i4 within the body III of the carburetor since said diaphragm is exposed to the manifold vacuum through the orifice 2i, line 41, bore 45, and passage 46a of the head 4|. A second or lower diaphragm 65 is diiposed within a diaphragm chamber 66 which is provided in the lower portion of the body 25 below the web 28. This lower diaphragm ha its peripheral portion clamped between the lower end of the body 25 and a diaphragm case 81 which is suitably secured to the body. The case is provided with an air vent 68 which communicates with the space below the diaphragm 05. A valve member 69 having an insert Ill of flexible or elastic material is secured axially of the diaphragm 65 and is arranged to be moved upwardly into engagement with the lower end of the tubular valve stem 34 and when so en-.

gaged, as illustrated in dotted lines in Figure 3. closes the bore of said stem. The diaphragm 65 has its upper surface exposed within the chamber C of the body 25 and is therefore exposed through the line l8 and inlet tube I! to the Venturi vacuum within the body it) of the gas mixer. Thus, it will be seen that the upper diaphragm 48 is exposed to the vacuum in the engine manifold above the throttle valve I4, while the lower diaphragm 65 is exposed to the Venturi vacuum.

As previously pointed out, the manifold vacuum under idling conditions is relatively high and is much higher than the Venturi vacuum because the restriction of flow through the carburetor is at the throttle valve i4. As the load increases and the throttle valve moves toward an open position, the manifold vacuum proportionately decreases, while the Venturi vacuum proportionately increases. portion of the operating range, the manifold vacuum is greater than the Venturi vacuum, and therefore, it is desirable to control the position of the main fuel valve 32 by the upper diaphragm 48, because the higher vacuum provides for more accurate control. However. when the engine is operating under full load, with the throttle valve l4 wide open, the Venturi vacuum is equal to or greater than the manifold vacuum, and at such time, the Venturi vacuum acting upon the lower diaphragm 65 is suflicient to accurately control the position of the main fuel valve. The apparatus hereinbefore described will operate to utilize the higher manifold vacuum to control the main fuel valve until such time as said manifold vacuum decreases to the point where it is insufficient to support the weight of the main valve assembly; when this decrease in the manifold vacuum has occurred, the proportionate, increase in the Venturi vacuum has raised said Venturi vacuum sufflciently to support the main valve assembly, whereby subsequent control of said assembly is carried out by the Venturi vacuum;

In the operation of the device, when the engine to which the apparatus is applied is not operating, the parts are in the position shown in Figure-2, with the diaphragms 48 and 65 in a lowered position and the main fuel valve 32 seated, the lower diaphragm 65 being spaced from the lower end of the stem 34. Also, at this time, the valve member V within the tubular Throughout the major housing 53 is held in its seated position by the spring I: and the upstanding pin it on said valve member is spaced from the set screw 84. The coil spring 55 which acts on the upper diea phragm 48 and on the valve stem and valve ele-- ment :2 connected thereto, positively holds the main fuel valve 32 in its seated or shut-oi! position.

' When the engine is startedand is operating at an idling speed the butterfly valve i4 of the carburetor is in the position shown in Figure 1, that is, said valve is substantially closed t strict flow through the body of the gas mixer. The manifold vacuum is acting through the oriflce 2|, line 41, bore 45, passage 4M and chamber 44 upon the upper diaphragm 48 within said chamber. This vacuum is sumcient to lift the diaphragm and its associate parts, whereby the main fuel valve 32 is lifted from its seat to permit a flow of gas from the supply line 24 to the gas mixer and then to the engine. It is desirable at this time that the main fuel valve 32 be maintained in a. predetermined open position to supply exactly the proper amount of gas to the 25 engine for efllcient idling. Since the throttle valve I4 is substantially closed at this time, the action of the Venturi suction upon the lower diaphragm 65 is not sumcient to lift this diaphragm upwardly since the weight of said diaso phragm is greater than the vacuum at the venturi during idling. With such arrangement under idling conditions, the position of the main fuel valve 32 is controlled solely by the manifold vacuum acting upon the upper diaphragm 4..

In order to lift the main valve 32 to a proper position and maintain the valve in such position, the control valve V comes into operation. Upon the initial lifting of the valve assembly due to the action of the manifold vacuum upon the upper diaphragm valve, the housing 53 as well as the valve element V carried therein are lifted. This upward movement continues until the upstanding pin 8| on the valve element strikes the lower end of the adjusting screw 64 to prevent further upward movement of the valve member V. However, the valve assembly, including the diaphragm 48 and housing 53 continues to move upwardly so as to move the seat 62 away from the inclined surface 60 of the valve member V. When this occurs, a flow may occur from the chamber C of the body 25 upwardly through the tubular valve stem 34, housing 5: and opening 56, then through the bore 45 and passage 464 into chamber 44 of the head 4|. The volume of flow through the housing 53 and into the chamber 44 is controlled by the taper or incline of the surface 80 of the valve member V. As soon as the valve V has moved to a position permitting fiuid to flow into the chamber 44 as fast as air, or other fluid, is withdrawn from the chamber through the line 41, further movement of the diaphragm 48 and the main fuel valve 32 is halted. When this condition occurs within the chamber 44, the vacuum within said chamber is maintained constant with the result that the main fuel valve will be suspended in a predetermined open position to permit a predetermined flow of gas to the engine. So long as the engine is idling, and the throttle valve I4 is not moved from the position shown in Figure 1, the main fuel valve 32 remains in such position.

From the foregoing, it is obvious that the adlustment of the set screw 64 controls the distance which the main fuel valve 32 is raised be- 75 cause lifting of the fuel valve continues until the controi'valve V strikes the set screw and opens to admit a flow to the chamber 44. Therefore,

flow into the chamber B is accomplished and thus, the main valve will be moved to a higher position before its movement is halted. Similarly, by reducing the angle, the upward movement of the main fuel valve 32 may be halted in a lower position.

As above stated, so long as the throttle valve I4 remainsin the position shown in Figure 1, the main fuel valve 32 will be maintained in a predetermined position to permit a predetermined volume of gas to flow to the engine. When the throttle valve is opened to accelerate the engine, the Venturi vacuum, that is, the suction effect of the jet located in the Venturi throat, is increased and this increase is suflicient to suspend the weight of the lower diaphragm 65, whereby said diaphragm is moved upwardly in the diaphragm chamber 66. This upward movement of the lower diaphragm moves the valve 10 carried by said lower diaphragm into close proximity to the 'lower end of the tubular valve stem 34, whereby the bore of said stem is restricted and flow throughthe stem and to the chamber 44 above the upper diaphragm 48 is reduced. As soon as the valve I restricts the flow through the tubular stem and to the chamber 44, the balanced condition in said chamber is upset and the manifold vacuum acting on the diaphragm 48 lifts said diaphragm a further distance to further open the main fuel valve. Such lifting moves the lower end of the stem away from the valve of the lower diaphragm and the lifting continues until the flow through the stem into the chamber 44 again equals the withdrawal of air or fluid from said chamber through the line 41, at which time further movement is halted. Thus, as the throttle valve I4 is operated, the lower diaphragm 65 coacts with the stem 34 and functions to permit the manifold vacuum to control the position of the main valve assembly. In actual practice, the lower diaphragm floats or is suspended and moves relative to the stem to restrict flow or permit increased flow to the chamber 44, whereby the upper diaphragm 48 may accurately position the main valve.

It is noted that upon initial opening of the throttle valve, the increased suction at the venturi is suflicient to lift the lower diaphragm 65 but would not be suilicient to lift the main valve assembly against the spring 55 so that even if the lower diaphragm engaged the stem at this time, it could not raise the valve but would merely close the bore of the stem and thereby increase the vacuum in the chamber 44 above the upper diaphragm. The manifold vacuum acting on the upper diaphragm is greater than the Venturi vacuum following the initial opening of the throttle valve l4 and thus, as the throttle is moved from the position in Figure 1, said manifold vacuum is sufficient to further lift the fuel valve and its associate parts upwardly.

As the throttle valve is opened further, this action is repeated, that is, the lower diaphragm moves upwardly toward the stem and restricts flow therethrough to allow the manifold vacuum to lift the main 'fuel valve further. Of course, if the throttle valve I4 is moved toward closed position, the Venturi vacuum decreases and the main fuel valve is lowered by the reduction in vacuum in the chamber 44.

As explained, while the Venturi vacuum proportionately increases, as the throttle valve moves toward a wide open position which would be at a time when the engine is under full load, the manifold vacuum gradually decreases. When the throttle is moved to wide open position, the manifold vacuum has decreased to minimum and may not be suilicient to accurately control the position of the main valve assembly; however, at wide open position of the throttle valve I4, the vacuum at the Venturi has increased to a point which is suflicient, not only to suspend the lower diaphragm 65 but also to sustain the entire weight of the valve assembly 32 and thus, the valve 10 engages the stem 30 and continued subsequent movement of the lower diaphragm raises said valve 32. The control of the valve 32 from this point on is accomplished solely by the lower diaphragm and Venturi vacuum. Thus, it becomes manifest that the manifold vacuum is utilized to control the position of the fuel valve until such time as said manifold vacuum is insuflicient and the Venturi vacuum becomes suiiicient to support said valve.

It is obvious that when the diaphragm 65 is in a raised position holding its valve 10 in engagement with the tubular valve stem, any closing of the main throttle valve M will result in a decrease of the Venturi vacuum and a proportionate increase in the manifold vacuum. This would immediately result in a separation of the valve 10 from the lower end of the tubular stem 34 and would permit a flow through the stem into the chamber 44 to halt further upward movement of the upper diaphragm 48 and valve 32. By utilizing the higher manifold vacuum throughout the major portion of the operating range, it is possible to employ the coil spring 55 which will assure positive seating of the valve element 32 when the device is not operating. The lower diaphragm 65 which is actuated by the ,Venturi vacuum is utilized to coact with the tubular valve stem so that the manifold vacuum may be permitted to properly act upon the upper diaphragm 48. It will be obvious that the lower diaphragm 65 will float or move relative to the end of. the stem 34 in accordance with the loads under which the engine is operating and under substantially full load will engage and lift the stem to control the position of the valve; in this manner, the main fuel valve 32 will be maintained in a, predetermined or proper position to supply the desired volume of gas to the engine under all operating conditions.

Although the device has been illustrated as controlling a gaseous fuel to a gas mixer, it is obvious that an ordinary gasoline carburetor may be substituted for the mixer. The connections with the control device A would be the same and an eflicient control of the liquid fuel to said carburetor would be had. of course, itis apparent that the device may be used with any type of internal combustion engine.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made,

I Patent is:

1. A gas carbureting apparatus for an intemal combustion engine including, a gas mixer having an air inlet and a gas inlet and a combined air and gas outlet connected to the engine intake manifold, said mixer also having a throttle valve disposed therein for controlling the fiow to the engine, a body connected with the fuel inlet, a fuel valve within the body for controlling the flow of fuel to the fuel inlet of the gas mixer, a vacuum responsive element connected to the fuel valve and exposed to the manifold vacuum of the engine downstream of the throttle valve for actuating said fuel valve, and a second vacuum responsive member movable independently of the main fuel valve and exposed to the vacuum in the mixer upstream of the throttle valve, said last named vacuum responsive member co-acting with the first vacuum responsive element whereby said first element controls the position of the main fuel valve until such time as the vacuum in the mixer upstream of the throttle valve equals or exceeds the manifold vacuum.

2. A gas carbureting apparatus as set forth in claim 1, wherein the vacuum responsive element and member are flexible diaphragms with their peripheral portions secured in fixed position and their central portions movable by the vacuum acting thereon.

3. A gas carbureting apparatus for an internal combustion engine including, a gas mixer having an air inlet and a gas inlet and a combined air and gas outlet connected to the engine intake manifold, said mixer also having a throttle valve disposed therein for controlling the flow to the engine, a body connected with the fuel inlet, a fuel valve within the body for controlling the flow of fuel to the fuel inlet of the gas mixer, said body having an upper chamber communicating with the engine manifold, a vacuum responsive element within said chamber and connected with the fuel valve, whereby said valve is moved by the manifold vacuum acting upon the element, means for limiting the movement of the vacuum responsive element by admitting a flow of fluid into the .chamber to maintain a predetermined vacuum in said chamber, and a second vacuum responsive member exposed to the vacuum in the mixer upstream from the throttle valve for restricting the flow into said chamber whereby when said member is actuated to restrict the fiow to the chamber, the first vacuum responsive element may be further actuated by the manifold vacuum to change the position of the fuel valve.

4. A gas carbureting apparatus including, a gas mixer having therein a suction passage with an air intake, a Venturi throat and a throttle valve and also having a fuel inlet delivering fuel at the Venturi throat, a body connected with the fuel inlet and having a fuel line extending thereto whereby fuel passes through the body and to the inlet of the mixer, a main fuel valve assembly within the body including a fuel valve for controlling flow to the mixer and also including a vacuum responsive element connected with the valve for actuating the same, said element being exposed to the vacuum in the engine manifold downstream of the throttle valve of the mixer so as to be actuated by said vacuum, means forming part of the assembly and actuated by the movement thereof for limiting the movement of the vacuum responsive element and fuel valve. and a second vacuum responsive member exposed to and operated by the Venturi vacuum of the mixer for co-acting with the valve assembly to permit the first mentioned vacuum responsive member and assembly to be moved further by the manifold vacuum to further open the main fuel valve beyond the point at which the limiting means galts the movement of said element and assem- 5. An apparatus as set forth in claim 4, wherein the co-action of the member with the assembly is attained by the movement of the second vacuum responsive member relative to the lower end of the assembly, the control of the position of the fuel valve being transferred to the second member when the Venturi vacuum acting on said second member increases to equal or exceed the manifold vacuum.

6. A gas carbureting apparatus including. a gas mixer having therein a suction passage with an air intake, a Venturiv throat and a throttle valve and also having a fuel inlet delivering fuel at the Venturi throat, a body connected with the fuel inlet and having a fuel line extending thereto whereby fuel passes through the body and to the inlet of the mixer, said body having a chamber in its upper portion, a main fuel valve assembly including a tubular valve stem having a fuel valve secured to its lower portion for controlling flow through the body, the upper portion of said stem communicating with th chamber in said body, a vacuum responsive element in said chamber and secured to the stem whereby movement of the element imparts movement to the fuel valve, means for establishing communication between the chamber above the element and the intake manifold of the engine whereby the engine manifold actuates the vacuum responsive element and the fuel valve attached thereto, means for normally closing the upper end of the valve-stem to seal the chamber and thereby permit the manifold vacuum to actuate the vacuum responsive element, means for opening said closure means upon a predetermined movement of the element and valve assembly to allow a flow into said chamber and thereby maintain a predetermined vacuum in said chamber, and a second vacuum responsive member exposed to the Venturi vacuum of the gas mixer for co-acting with thev lower end of the tubular stem to control and restrict flow through said stem to vary the vacuum in the chamber in accordance with the vacuum in the venturi of the mixer.

. diaphragms having their peripheral portions secured to the body with their central portions movable by the suction acting thereon.

9. A gas carbureting apparatus including, a gas mixer having therein a suction passage with an air intake, a Venturi throat and a throttle valve and also having a fuel inlet delivering fuel at the Venturi throat, a body connected with the fuel inlet and having a fuel line extending thereto whereby fuel passes through the body and to the inlet of the mixer, said body having a chamher in its upper portion, a main fuel valve assembly including a tubular valve stem having a fuel valve secured to its lower portion for controlling fiow through the body, the upper portion of said stem communicating with the chamber in said body, a vacuum responsive element in said chamber and secured to the stem whereby movement of the element imparts movement to the fuel valve, means for establishing communication between the chamber above the element and the intake manifold of the engine whereby the engine manifold actuates the vacuum responsive element and the fuel valve attached thereto, a spring-pressed valve for normally closing the bore of the valve stem to seal the chamber to permit actuation of the vacuum responsive element by the manifold vacuum, an abutment within the body and adapted to be engaged by the valve upon predetermined movement of the vacuum responsive element and valve assembly for opening said valve to allow a fiow into the chamber and thereby maintain a predetermined vacuum in the chamber to limit movement of the valve assembly, and a second vacuum responsive member exposed to the Ventdri vacuum of the gas mixer for co-acting with the lower end of the tubular stem to control flow through said stem to vary the vacuum in the chamber and permit additional movement of the valve assembly by the first mentioned vacuum responsive element in accordance with the vacuum in the Venturi of the mixer.

10. The apparatus as set forth in claim 9. wherein the abutment is adjustable so that the valve assembly may be moved any desired distance before the spring-pressed valve is opened to halt further movement thereof.

11. The apparatus as set forth in claim 9, wherein the second vacuum responsive member is engageable with the lower end of the stem upon a suflicient upward movement thereof, whereby when the Venturi vacuum increases to equal or exceed the manifold vacuum, the control of the fuel valve is transferred from the first vacuum responsive element to the second vacuum responsive member.

12. A gas carburetor apparatus for internal combustion engines including, a gas mixer having a Venturi throat and also having a throttle valve'and air inlet, a fuel line for conducting fuel to the mixer, a main fuel valve connected in the fuel line for controlling the flow of fuel to the mixer, vacuum responsive means actuated by the manifold vacuum of the engine and connected with the fuel valve for operating said valve to control the position thereof, and a second vacuum responsive means independent of the first means and actuated by the Venturi vacuum of the gas mixer for co-acting with said first means to control the position to which the fuel valve and said first mentioned vacuum responsive means is moved by the manifold vacuum.

13. The apparatus as set forth in claim 12, wherein the second pressure responsive means is adapted to engage the fuel valve-whereby when the Venturi vacuum increases to a point sufficient to sustain the weight of the fuel valve, the control of said valve is transferred to the second pressure responsive means. Y

14. The apparatus as set forth in claim 12, wherein each pressure responsive means is a diaphragm having its peripheral portion fastened in a fixed plane with its central portion movable by the vacuum acting thereon.

SAM-:P. JONES. 

